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New HVAC, pressure tests, IAQ

Folks:

We're completing a renovation of a 100 year old home (to the studs). We put in the new HVAC system including all new duck works (sheet metal ducts, looks like quality work, all done by the tradesmen themselves). The HVAC company is a very old, long standing company with a great reputation. But, they do not perform a pressure test on the system unless I push for it (and pay an extra $800).

For IAQ reasons, I want to make sure no air from the basement or garage (where the furnace is) makes its way into the house and that there is a slightly positive pressure in the house. We do have up to 20% outside air as part of the return/fresh air supply.

Any thoughts on the need for a pressure test on the system, how-to assure no air from the garage gets into the house and that a positive pressure is maintained in the home would be greatly appreciated.

We're
For IAQ reasons, I want to make sure no air from the basement or garage (where the furnace is) makes its way into the house and that there is a slightly positive pressure in the house. We do have up to 20% outside air as part of the return/fresh air supply.

Andrew

Dream on! The pressure from wind and stack effect will overcome any attempt to stop air movement throughout the structure. Best to keep the connected space clean of pollution. Providing a small amount of fresj make-up air to purge indoor pollutants and renew oxygen when occupied is a better solution. Always maintain <50%RH through all space to prevent mold growth espicially the basement. Green grass climates require supplemental dehumidification during the low/no cooling load weather to maintain <50%RH. Consider a ventilating dehumidifier to provide all of the above. High efficiency v dehus are less costly to operate. Dehu TB

I paid less than half that to a HVAC co that specializes in airflow issues and got a nearly 3 hrs blower door test, pressure pan, flow hood, home/room pressures, and a thermal image scan of my entire home.

I found all of the above tests useful as a new HVAC owner as you really don't know how good a job the contractor did till all the numbers are evaluated. Another useful test is the HVAC static pressure which my contractor did only after weeks of phone calls.

Companies that do the above tests are usual very few and often don't do installs so you should find out exactly what you're getting for your $$$.

Also, what sort of HVAC equip did you have installed?

Originally Posted by andrew1cohen

Folks:

We're completing a renovation of a 100 year old home (to the studs). We put in the new HVAC system including all new duck works (sheet metal ducts, looks like quality work, all done by the tradesmen themselves). The HVAC company is a very old, long standing company with a great reputation. But, they do not perform a pressure test on the system unless I push for it (and pay an extra $800).

For IAQ reasons, I want to make sure no air from the basement or garage (where the furnace is) makes its way into the house and that there is a slightly positive pressure in the house. We do have up to 20% outside air as part of the return/fresh air supply.

Any thoughts on the need for a pressure test on the system, how-to assure no air from the garage gets into the house and that a positive pressure is maintained in the home would be greatly appreciated.

Do not pay, wait forum rules..........I would get another quote from another company to come in and pressure test the duct. You may just want to have the company just seal the duct as the should in the first place. Also, you could look the system over and tape or use mastic to seal it yourself. I think the reason the one company is so high is because they might be subbing that job out.